[Devel] [PATCH RHEL8 COMMIT] ploop: Refactoring in submit_cluster_cow()

[Konstantin Khorenko]

The commit is pushed to "branch-rh8-4.18.0-240.1.1.vz8.5.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-240.1.1.vz8.5.31
------>
commit 9551b75cbf7bc492180d9b5c7457de8e1364f51c
Author: Kirill Tkhai <ktkhai at virtuozzo.com>
Date:   Mon May 24 12:57:18 2021 +0300

    ploop: Refactoring in submit_cluster_cow()
    
    Move code up and remove duplicate REQ_OP_READ assignment.
    
    Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
    
    =====================
    Patchset description:
    
    ploop: Truncate top delta from kernel
    
    and refactoring at tail.
    
    https://jira.sw.ru/browse/PSBM-129278
    
    Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/md/dm-ploop-map.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/drivers/md/dm-ploop-map.c b/drivers/md/dm-ploop-map.c
index 07980d8f73b3..fced934b5b7a 100644
--- a/drivers/md/dm-ploop-map.c
+++ b/drivers/md/dm-ploop-map.c
@@ -1176,18 +1176,18 @@ int submit_cluster_cow(struct ploop *ploop, unsigned int level,
 		       unsigned int cluster, unsigned int dst_cluster,
 		       void (*end_fn)(struct ploop *, int, void *), void *data)
 {
+	struct ploop_cow *cow = NULL;
 	struct pio *pio = NULL;
-	struct ploop_cow *cow;
 
 	/* Prepare new delta read */
 	pio = alloc_pio_with_pages(ploop);
-	if (!pio)
-		goto err;
-	init_pio(ploop, REQ_OP_READ, pio);
-
 	cow = kmem_cache_alloc(cow_cache, GFP_NOIO);
-	if (!cow)
+	if (!pio || !cow)
 		goto err;
+	init_pio(ploop, REQ_OP_READ, pio);
+	pio_prepare_offsets(ploop, pio, cluster);
+	pio->endio_cb = ploop_cow_endio;
+	pio->endio_cb_data = cow;
 
 	cow->ploop = ploop;
 	cow->dst_cluster = BAT_ENTRY_NONE;
@@ -1195,11 +1195,6 @@ int submit_cluster_cow(struct ploop *ploop, unsigned int level,
 	cow->end_fn = end_fn;
 	cow->data = data;
 
-	pio_prepare_offsets(ploop, pio, cluster);
-	pio->bi_op = REQ_OP_READ;
-	pio->endio_cb = ploop_cow_endio;
-	pio->endio_cb_data = cow;
-
 	init_pio(ploop, REQ_OP_WRITE, &cow->hook);
 	add_cluster_lk(ploop, &cow->hook, cluster);
 
@@ -1209,6 +1204,7 @@ int submit_cluster_cow(struct ploop *ploop, unsigned int level,
 err:
 	if (pio)
 		free_pio_with_pages(ploop, pio);
+	kfree(cow);
 	return -ENOMEM;
 }